Document ejecting mechanism and document feeder using the same

ABSTRACT

A document ejecting mechanism includes an output roller, a roller shaft, an idle roller, an idle shaft and an adjusting device. The roller shaft inserts through the output roller, which rotates the idle roller. The idle shaft inserts through the idle roller. The adjusting device adjusts a distance between the output roller and the idle roller. A document feeder using the document ejecting mechanism is also disclosed.

This application claims priority of No. 096126496 filed in Taiwan R.O.C. on Jul. 20, 2007 under 35 USC 119, the entire content of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of Invention

The invention relates to a document ejecting mechanism and a document feeder using the same, and more particularly to a shiftable document ejecting mechanism and a document feeder using the same.

2. Related Art

In order to scan two sides of a document using a single scanning module, a conventional scanner has to be equipped with an automatic document feeder for turning the document twice or more than two times. Thus, transporting rollers have to be rotated clockwise and counterclockwise so as to transport the document in the passageways of the feeder in two opposite directions.

However, the transporting rollers which rotate clockwise and the ones which rotate counterclockwise may tug the same document at the same time in opposite directions, due to the designs of the mechanism and the structure, thereby tearing the sheet or wearing the rollers quickly. The conventional drawbacks may be clearly understood according to the advantages of the following preferred embodiments.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a document ejecting mechanism capable of releasing a document being transported to prevent the document from being torn up or to prevent a roller from being worn out rapidly, and a document feeder using the same.

To achieve the above-identified object, the invention provides a document ejecting mechanism including an output roller, a roller shaft, an idle roller, an idle shaft and an adjusting device. The roller shaft inserts through the output roller. The idle roller is rotated by the output roller. The idle shaft inserts through the idle roller. The adjusting device adjusts a distance between the output roller and the idle roller.

To achieve the above-identified object, the invention also provides a document feeder including a sheet input tray, a group of passageways, an image processing region and a document transporting device. The sheet input tray stores a document. The group of passageways is connected to the sheet input tray. The image processing region is disposed in the group of passageways. The document transporting device transports the document from the sheet input tray into the group of passageways with each of a front side and a back side of the document being transported across the image processing region once, and then transports the document to a sheet output tray of the document feeder. The document transporting device includes a document ejecting mechanism. The document ejecting mechanism includes an output roller, a roller shaft inserting through the output roller, an idle roller rotated by the output roller, an idle shaft inserting through the idle roller and an adjusting device for adjusting a distance between the output roller and the idle roller.

Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention.

FIG. 1 is a schematic illustration showing a document feeder applied to a scanner according to a preferred embodiment of the invention.

FIG. 2 is a schematic illustration showing connections to a control circuit of FIG. 1.

FIG. 3 is a schematic illustration showing a document ejecting mechanism according to a first embodiment of the invention.

FIG. 4 is a schematic illustration showing a document ejecting mechanism according to a second embodiment of the invention.

FIG. 5 is a schematic illustration showing a document ejecting mechanism according to a third embodiment of the invention.

FIG. 6 is a schematic illustration showing a document ejecting mechanism according to a fourth embodiment of the invention.

FIG. 7 is a schematic illustration showing a document ejecting mechanism according to a fifth embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.

FIG. 1 is a schematic illustration showing a document feeder 1 applied to a scanner according to a preferred embodiment of the invention.

FIG. 2 is a schematic illustration showing connections to a control circuit of FIG. 1. Referring to FIGS. 1 and 2, the document feeder 1 of this embodiment includes a sheet input tray 10, a group of passageways 20, an image processing region 30, a document transporting device 40 and a sheet output tray 50.

The sheet input tray 10 stores a document D or a plurality of documents D.

The group of passageways 20 is connected to the sheet input tray 10. Specifically speaking, the group of passageways 20 includes first to fifth passageways 21 to 25. The first passageway 21 starts from point A to point B and is connected to the sheet input tray 10. The second passageway 22 starts from point B to point C and is connected to the first passageway 21. The image processing region 30 is disposed on the second passageway 22 of the group of passageways 20. In this embodiment, the image processing region 30 is a scan region, and a document being transported across the scan region is scanned by a scanning module 90. The third passageway 23 starts from point C to a sheet outlet 23A and is connected to the second passageway 22 and the sheet output tray 50. The fourth passageway 24 starts from point C to point B and is connected to the first passageway 21, the second passageway 22 and the third passageway 23. The fifth passageway 25 starts from a guiding rod 26 to a sheet outlet 25A and is connected to the third passageway 23 and the sheet output tray 50. The document is finally outputted from the sheet outlet 25A.

The document transporting device 40 transports the document D, stored in the sheet input tray 10, into the group of passageways 20 with each of a front side and a back side of the document D being transported across the image processing region 30 once or more than one time, and then transports the document D to the sheet output tray 50 of the document feeder 1.

The document transporting device 40 includes a document ejecting mechanism 41, a sheet feeding mechanism 42 and a document transporting mechanism 43. The document ejecting mechanism 41 is disposed on the third passageway 23, and includes an output roller 41A, a roller shaft 41A1, an idle roller 41B, an idle shaft 41B1 and an adjusting device 41C. The roller shaft 41A1 inserts through the output roller 41A. The idle roller 41B is rotated by the output roller 41A. The idle shaft 41B1 inserts through the idle roller 41B. The adjusting device 41C adjusts a distance L between the output roller 41A and the idle roller 41B. The sheet feeding mechanism 42 transports the document D from the sheet input tray 10 into the group of passageways 20.

The document transporting mechanism 43 includes a plurality of document transporting rollers 44 and a plurality of document transporting idle rollers 45, wherein one of the document transporting rollers 44 and the output roller 41A are driven by the same reversible power source 80. Herein, the reversible power source, such as a motor, can rotate the roller clockwise or counterclockwise.

In addition, the document feeder 1 may further include a control circuit 60 and a document detector 70. The control circuit 60 controls the overall operation of the document feeder 1 and is connected to the reversible power source and the adjusting device 41C.

The document detector 70, connected to the control circuit 60 and disposed on the group of passageways 20, detects a position of the document D and thus outputs a position signal to the control circuit 60. Thus, the control circuit 60 controls the adjusting device 41C to adjust the distance L between the output roller 41A and the idle roller 41B and controls the reversible power source to drive the output roller 41A and one of the document transporting rollers 44 to rotate clockwise or counterclockwise according to the position signal. Thus, the document D can be released at the proper timing for the following purpose.

When a duplex scanning process is being performed, the sheet feeding mechanism 42 transports the document from the sheet input tray 10 into the first passageway 21. At this time, the document transporting roller 44 and the output roller 41A are rotated counterclockwise to transport the document D from the first passageway 21 to the second passageway 22. Then, the document D pushes away a guide sheet 27 and then enters the third passageway 23. Next, it is obtained through a document detector 71 that the trailing edge of the document D has been transported past the guiding rod 26, and the document transporting roller 44 and the output roller 41A are rotated clockwise to transport the document D from the third passageway 23 to the fourth passageway 24. Then, it is obtained through the document detector 70 that the document is going to reach the document transporting idle roller 45 and the document transporting roller 44. At this time, the document transporting roller 44 and the output roller 41A have to be rotated counterclockwise. If the leading edge of the document D does not move off the output roller 41A and the idle roller 41B, and the document D is tugged by both of the output roller 41A and the document transporting roller 44 in opposite directions. Thus, the document D may be torn or the output roller 41A and the document transporting roller 44 may be worn out quickly.

According to the document ejecting mechanism of the invention, the output roller 41A and the idle roller 41B can release the document D to avoid this problem under this circumstance. The configuration of the adjustable document ejecting mechanism will be described in the following.

FIG. 3 is a schematic illustration showing a document ejecting mechanism according to a first embodiment of the invention. Referring to FIG. 3, the document ejecting mechanism 41 of this embodiment includes the output roller 41A, the roller shaft 41A1, the idle roller 41B, the idle shaft 41B1 and the adjusting device 41C. The roller shaft 41A1 inserts through the output roller 41A. The idle roller 41B is rotated by the output roller 41A. The idle shaft 41B1 inserts through the idle roller 41B. The adjusting device 41C adjusts the distance L between the output roller 41A and the idle roller 41B. The adjusting device 41C includes a driving unit, wherein the driving unit comprises a solenoid 41C1, for moving the idle shaft 41B1 of the idle roller 41B in a direction indicated by the arrow. The force for pressing the output roller 41A against the idle roller 41B may also be provided by a spring or a torsional spring 41D.

FIG. 4 is a schematic illustration showing a document ejecting mechanism according to a second embodiment of the invention. As shown in FIG. 4, this embodiment is similar to the first embodiment except that the solenoid 41C1 of the adjusting device 41C moves the roller shaft 41A1 of the output roller 41A.

According to the first and second embodiments, it is obtained that a driving unit 41C1 is for moving one end of at least one of the roller shaft 41A1 and the idle shaft 41B1. In addition, the adjusting device 41C can move one end of the idle shaft 41B1 from a first position P1 to a second position P2 in the first embodiment. The document ejecting mechanism 41 may further include a torsional spring 41D, which has one end connected to the idle shaft 41B1 and the other end connected to a housing (not shown), and provides a restoring force to the idle shaft 41B1 to move the one end of the idle shaft 41B1 from the second position P2 to the first position P1. In the following embodiment, the adjusting device only drives the idle shaft. However, one of ordinary skill in the art may easily understand that the adjusting device may also drive the roller shaft. FIG. 5 is a schematic illustration showing a document ejecting mechanism according to a third embodiment of the invention. As shown in FIG. 5, this embodiment is similar to the first and second embodiments except that the adjusting device 41C includes a leverage mechanism 41C5 having one end contacting with one end of the idle shaft 41B1. The driving unit 41C1 drives the other end of the leverage mechanism 41C5 to make the leverage mechanism 41C5 generate a leverage motion to move the idle shaft 41B1 for the purpose of adjusting the distance between the output roller and idle roller. In this embodiment, the driving unit 41C1 comprises a solenoid and a driving part 41C11, wherein the solenoid drives the driving part, the driving part moves the other end of the leverage mechanism 41C5 and the one end of the leverage mechanism is driven to move the idle shaft 41B1.

FIG. 6 is a schematic illustration showing a document ejecting mechanism according to a fourth embodiment of the invention. Referring to FIG. 6, the document ejecting mechanism 41 of this embodiment further includes a rod 41C2 connected to the idle shaft 41B1. The adjusting device 41C includes a driving unit 41C1, wherein the driving unit comprises a solenoid, for moving one end of the rod 41C2 to move the idle shaft 41B1.

In addition, the document ejecting mechanism 41 of this embodiment may further include a sleeve assembly 41C6 for connecting the rod 41C2 and the idle shaft 41B1. The idle shaft 41B1 inserts through a first sleeve 41C61 of the sleeve assembly 41C6. The rod 41C2 inserts through a second sleeve 41C62 of the sleeve assembly 41C6. The adjusting device 41C moves the one end of the rod 41C2 from a first position P1 to a second position P2. The document ejecting mechanism may further include a torsional spring 41D, having one end connected to the rod 41C2, for providing a restoring force to the rod 41C2 to move the one end of the rod 41C2 from the second position P2 to the first position P1.

FIG. 7 is a schematic illustration showing a document ejecting mechanism according to a fifth embodiment of the invention. Referring to FIG. 7, the adjusting device 41C of the document ejecting mechanism 41 according to this embodiment includes a leverage mechanism 41C5 having one end contacting with the one end of the rod 41C2. The driving unit 41C1 moves the other end of the leverage mechanism 41C5 and the one end of the leverage mechanism is thus driven to move the rod 41C2. In this embodiment, the driving unit 41C1 comprises a solenoid and a driving part 41C11, wherein the solenoid drives the driving part, the driving part moves the other end of the leverage mechanism 41C5 and the one end of the leverage mechanism is driven to move the rod 41C2.

Therefore, one end of the driving shaft or the rod may be moved to separate the output roller 41A from the idle roller 41B effectively according to the document ejecting mechanism and the document feeder of the invention. Thus, it is possible to prevent the document from being torn in the passageway.

While the invention has been described by way of examples and in terms of preferred embodiments, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications. 

1. A document ejecting mechanism, comprising: an output roller; a roller shaft inserting through the output roller; an idle roller rotated by the output roller; an idle shaft inserting through the idle roller; and an adjusting device, for adjusting a distance between the output roller and the idle roller.
 2. The document ejecting mechanism according to claim 1, wherein the adjusting device comprises: a driving unit, for driving one end of at least one of the roller shaft and the idle shaft.
 3. The document ejecting mechanism according to claim 2, wherein the adjusting device further comprises: a leverage mechanism, wherein one end of the leverage mechanism contacts with the one end of one of the roller shaft and the idle shaft, wherein the driving unit drives the other end of the leverage mechanism to drive the one end of the leverage mechanism to move one of the roller shaft and the idle shaft.
 4. The document ejecting mechanism according to claim 3, wherein the driving unit comprises a solenoid and a driving part, wherein the solenoid drives the driving part, the driving part moves the other end of the leverage mechanism and the one end of the leverage mechanism is driven to move one of the roller shaft and the idle shaft.
 5. The document ejecting mechanism according to claim 2, wherein the adjusting device moves the one end of one of the roller shaft and the idle shaft from a first position to a second position, and the document ejecting mechanism further comprises: a torsional spring, wherein one end of the torsional spring connected to one of the roller shaft and the idle shaft, and the torsional spring is for providing a restoring force to one of the roller shaft and the idle shaft to move the one end of one of the roller shaft and the idle shaft from the second position to the first position.
 6. The document ejecting mechanism according to claim 1, further comprising: a rod connected to one of the roller shaft and the idle shaft, wherein the adjusting device comprises a driving unit for moving one end of the rod to shift one of the roller shaft and the idle shaft.
 7. The document ejecting mechanism according to claim 6, wherein the adjusting device comprises: a leverage mechanism, wherein one end of the leverage mechanism contacts with the one end of the rod, wherein the driving unit drives the other end of the leverage mechanism to drive the one end of the leverage mechanism to move the rod.
 8. The document ejecting mechanism according to claim 7, wherein the driving unit comprises a solenoid and a driving part, wherein the solenoid drives the driving part, the driving part moves the other end of the leverage mechanism and the one end of the leverage mechanism is driven to move the rod.
 9. The document ejecting mechanism according to claim 6, further comprising: a sleeve assembly for connecting the rod to one of the roller shaft and the idle shaft, wherein one of the roller shaft and the idle shaft inserts through a first sleeve, and the rod inserts through a second sleeve.
 10. The document ejecting mechanism according to claim 6, wherein the adjusting device moves the one end of the rod from a first position to a second position, and the document ejecting mechanism further comprises: a torsional spring, having one end connected to the rod, for providing a restoring force to the rod to move the one end of the rod from the second position to the first position.
 11. A document feeder, comprising: a sheet input tray for storing a document; a group of passageways; an image processing region disposed in the group of passageways; and a document transporting device, for transporting the document from the sheet input tray into the group of passageways with each of a front side and a back side of the document being transported across the image processing region once, and then transporting the document to a sheet output tray of the document feeder, the document transporting device comprising a document ejecting mechanism, which comprises: an output roller; a roller shaft inserting through the output roller; an idle roller rotated by the output roller; an idle shaft inserting through the idle roller; and an adjusting device, for adjusting a distance between the output roller and the idle roller.
 12. The document feeder according to claim 11, wherein the document transporting device further comprises: a plurality of document transporting rollers and a plurality of document transporting idle rollers, wherein one of the document transporting rollers and the output roller is driven by one reversible power source.
 13. The document feeder according to claim 12, further comprising: a control circuit, connected to the reversible power source and the adjusting device; and a document detector, connected to the control circuit and disposed in the group of passageways, for detecting a position of the document and thus outputting a position signal to the control circuit, wherein the control circuit controls the adjusting device to adjust the distance between the output roller and the idle roller and controls the reversible power source to drive one of the document transporting rollers and the output roller to rotate clockwise or counterclockwise according to the position signal.
 14. The document feeder according to claim 11, wherein the adjusting device comprises: a driving unit for driving one end of at least one of the roller shaft and the idle shaft.
 15. The document feeder according to claim 14, wherein the adjusting device further comprises: a leverage mechanism having one end contacting with the one end of one of the roller shaft and the idle shaft, wherein the driving unit drives the other end of the leverage mechanism to drive the one end of the leverage mechanism to move one of the roller shaft and the idle shaft.
 16. The document feeder according to claim 15, wherein the driving unit comprises a solenoid and a driving part, wherein the solenoid drives the driving part, the driving part moves the other end of the leverage mechanism and the one end of the leverage mechanism is driven to move one of the roller shaft and the idle shaft.
 17. The document feeder according to claim 14, wherein the adjusting device moves the one end of one of the roller shaft and the idle shaft from a first position to a second position, and the document ejecting mechanism further comprises: a torsional spring, wherein one end of the torsional spring connected to one of the roller shaft and the idle shaft, and the torsional spring is for providing a restoring force to one of the roller shaft and the idle shaft to move the one end of one of the roller shaft and the idle shaft from the second position to the first position.
 18. The document feeder according to claim 11, wherein the document ejecting mechanism further comprises: a rod connected to one of the roller shaft and the idle shaft, wherein the adjusting device comprises a driving unit for moving one end of the rod to shift one of the roller shaft and the idle shaft.
 19. The document feeder according to claim 18, wherein the adjusting device comprises: a leverage mechanism, wherein one end of the leverage mechanism contacts with the one end of the rod, wherein the driving unit drives the other end of the leverage mechanism to drive the one end of the leverage mechanism to move the rod.
 20. The document feeder according to claim 19, wherein the driving unit has a solenoid and a driving part, wherein the solenoid drives the driving part, the driving part moves the other end of the leverage mechanism and the one end of the leverage mechanism is driven to move the rod.
 21. The document feeder according to claim 18, further comprising: a sleeve assembly for connecting the rod to one of the roller shaft and the idle shaft, wherein one of the roller shaft and the idle shaft inserts through a first sleeve, and the rod inserts through a second sleeve.
 22. The document feeder according to claim 18, wherein the adjusting device moves the one end of the rod from a first position to a second position, and the document ejecting mechanism further comprises: a torsional spring, wherein one end of the torsional spring connected to the rod, and the torsional spring is for providing a restoring force to the rod to move the one end of the rod from the second position to the first position. 